TWI591682B - Methods and apparatuses for effectively reducing gas residence time in a plasma processing chamber - Google Patents

Description

Method and apparatus for effectively reducing gas residence time in a plasma processing chamber

The present invention relates to a method and apparatus for effectively reducing gas residence time in a plasma processing chamber.

Plasma has long been used to process substrates (eg, wafers, flat panel displays, liquid crystal displays, and others) into electronic devices (eg, integrated circuit dies) for incorporation into a variety of electronic products (eg, smart phones, Computer and other).

In plasma processing, a plasma processing system having one or more plasma processing chambers can be used to process one or more substrates. In each chamber, plasma generation can use capacitive coupled plasma technology, inductively coupled plasma technology, electron cyclotron technology, microwave technology, and the like.

During processing of the wafer, for example, a reactive gas (which may use one or more types of gases) is introduced into the plasma processing zone and energized to form a plasma. For example, if a plasma is used to etch a planar portion of the substrate (relative to the bevel portion), the plasma is limited to the plasma processing region, which is concentrated over the substrate and generally with the substrate, the upper electrode, or the upper chamber wall. /Component and / or limit ring group is bounded. The plasma exposed surface is then etched, deposited, or otherwise treated using plasma.

During processing, the plasma interacts with the exposed areas on the substrate, and the interaction simultaneously treats the exposed areas and produces by-products. The by-product gas is then withdrawn as the plasma continues to be produced from the supplied reaction gas. Other components (ion or free radicals) in the plasma form certain pre-cursors that are critical to the sidewall protection of the etched structure to ensure an anisotropic etch. By way of example, such precursors can cause polymer deposition on the feature sidewalls. Good etching direction. Other precursors can advantageously result in some etch selectivity between films of different materials, which would otherwise be difficult to achieve.

Figure 1 shows a conventional plasma processing chamber 102 in a plasma processing system (which may have one or more chambers). In FIG. 1, the substrate 104 is shown mounted on an electrostatic chuck (ESC) 106 forming a lower electrode. The insulating ring 108 and the grounding ring 110 are shown surrounding the ESC 106. The plasma processing region 120 is shown bounded by a chamber top plate 122, a lower electrode/ESC 106, and a set of confinement rings 124. For example, in the case of a capacitively coupled plasma processing system, the chamber top plate 122 can represent the upper electrode. In other systems, the chamber ceiling can only represent the chamber structure used to limit the plasma.

The reaction gas is supplied via an external gas supply (known and not shown) via the gas plenum 130, which may also include a heating device to control the temperature of the upper electrode 122. In the example of FIG. 1, the plasma processing chamber 102 is a capacitively coupled plasma chamber and thus the chamber top plate 122 can represent an upper electrode that can be grounded, for example, or can have radio frequency (RF) energy.

The plasma generating power source 170, in the form of the RF power supply in the example of FIG. 1, supplies RF energy to the lower electrode/ESC 106 in the plasma processing region 120 to excite the plasma. In other chamber designs or chambers that use different plasma generation techniques, the plasma generating power source 170 can include multiple power sources to provide RF energy to different components of the chamber or can be another plasma generating technique other than RF. Type (eg microwave).

By-product gases can be vented through the sides of the chamber or the lower portion of the chamber or both. The components of the plasma processing chamber 102, as well as other existing plasma generating chambers (using capacitively coupled plasma or other plasmas produced using different plasma generating techniques), are well known and well known to those skilled in the art, and It will not be elaborated here.

It has been observed that in certain plasma processing chambers, there is some degree of process non-uniformity (in terms of processing rate or processing results) from the central region 150 of the substrate 104 to the edge region 152 of the substrate 105. When a narrow gap chamber is present (the narrow gap chamber indicates that the gap between the upper surface of the substrate and the lower surface of the upper electrode in the chamber is less than 10% of the diameter of the substrate) etching and/or processing a larger substrate ( For wafers such as 450 mm or larger, the problem of non-uniformity tends to deteriorate.

In some cases, etching of high aspect ratio features is susceptible to a phenomenon known as Aspect Ratio Dependent Etching (ARDE). Some evidence suggests that one of the mechanisms leading to ARDE is a reaction by-product that takes a relatively long time to move from deep structures (such as high depth) The lower portion of the hole (or groove) of the width ratio diffuses out to reach the surface of the wafer from which they can be drawn. The large increase in etch by-products at the bottom of the deep features slows the re-supply of new etchants to reduce their concentration. When the etch leading edge advances to a deeper portion of the feature, the above conditions result in a slowing of the etch leading edge (compared to the rate directly below the mask).

In view of the above, improved etching techniques and equipment are needed.

In one embodiment, the present invention is directed to a plasma processing system having at least one plasma processing chamber for processing a substrate. The plasma processing chamber includes a lower electrode for supporting the substrate and a chamber top plate disposed above the lower electrode such that the plasma processing region is present between the upper surface of the substrate and the top plate of the chamber during processing. The plasma processing system also includes a plasma generating power source for providing energy to generate plasma from the supplied reactive gas in the plasma processing region, and a light emitting device for emitting the first light into the plasma processing region. There is further included a light collecting device for receiving the second light, the second light representing a changed form of the first light (after the first light passes through the plasma processing region). Additionally comprising logic to analyze the second light to determine whether the parameter of the second light is equal to or exceeds the first threshold, or equal to or falls below the second threshold, wherein if the parameter of the second light is equal to or exceeds the first a threshold value, the logic transmits a first signal to reduce the amount of energy generated by the plasma provided by the plasma generating power source; if the parameter of the second light is equal to or falls below the second threshold value, the logic transmits the second signal to Increasing the amount of energy produced by the plasma provided by the plasma generating power source.

In still another embodiment, the present invention is directed to a method of processing a substrate in a plasma system having at least one plasma processing chamber, the chamber including at least one lower electrode for supporting the substrate, disposed over the lower electrode The chamber top plate (which causes the plasma processing region to exist between the upper surface of the substrate and the top plate of the chamber during processing) and the electricity used to provide energy to generate plasma from the supplied reactive gas in the plasma processing region The pulp produces a power source. The method includes providing a light emitting device for emitting a first light into a plasma processing region and a light collecting device for receiving a second light, the second light representing a changed form of the first light (processing the first light through the plasma After the region, logic is also included to analyze the second light to determine if the parameter of the second light exceeds the first threshold or falls below the second threshold. If the parameter of the second light is equal to or exceeds the first critical value, the method reduces the amount of energy generated by the plasma provided by the plasma generating power source. If the parameter of the second ray is equal to or falls below the second threshold, the method increases the amount of energy produced by the plasma provided by the plasma generating power source.

102‧‧‧The plasma processing chamber

104‧‧‧Substrate

106‧‧‧Electrical chuck

108‧‧‧Insulation ring

110‧‧‧ Grounding ring

120‧‧‧ Plasma processing area

122‧‧‧Case ceiling

124‧‧‧Restricted ring

130‧‧‧Gas Inflator

150‧‧‧Substrate center area

152‧‧‧Surface edge area

170‧‧‧ Plasma generated power

204‧‧‧The plasma processing chamber

206‧‧‧ lower electrode

208‧‧‧Substrate

210‧‧‧Cable ceiling

212‧‧‧The plasma processing area

214‧‧‧Lighting equipment

220‧‧‧Lighting equipment

222‧‧‧ lens

240‧‧‧RF power supply

280‧‧‧ Controller

304‧‧‧The plasma processing chamber

306‧‧‧ lower electrode

308‧‧‧Substrate

310‧‧‧Case ceiling

312‧‧‧ Plasma processing area

328‧‧‧Light diode

330‧‧‧Interference filter

340‧‧‧RF power supply

402‧‧‧Signal strength

420‧‧‧critical value

430‧‧‧critical value

The present invention is illustrated by the accompanying drawings in the drawings, and the More chambers) a conventional plasma processing chamber for ease of discussion.

2 shows a simplified diagram of a portion of an inventive chamber to reduce effective gas residence time to improve uniformity, in accordance with an embodiment of the present invention.

In accordance with an embodiment of the present invention, FIG. 3 shows a simplified diagram of a portion of an inventive chamber to reduce effective gas residence time to improve uniformity.

Figure 4 shows a plot of fluorescence or absorbed signal intensity as a function of time, in accordance with an embodiment of the present invention.

In accordance with an embodiment of the present invention, FIG. 5 shows a graph of the wavelength of the signal intensity versus fluorescence (which is emitted after a laser beam is emitted from the illumination device and received by the light-receiving device).

In accordance with an embodiment of the present invention, FIG. 6 shows a plot of signal intensity versus transmitted light (after a wide (white) spectral beam is emitted from the illumination device and received by the light-receiving device and after passing through the absorption medium).

In accordance with an embodiment of the present invention, Figure 7 shows a method for reducing the effective residence time of a gas to improve uniformity.

The invention will now be described in detail by reference to a few embodiments thereof illustrated in the drawings. In the following description, numerous details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without some of the specific details. In other instances, well-known process steps and/or structures are not described in detail to avoid unnecessarily obscuring the invention.

Different embodiments are described below, including methods and techniques. It should be borne in mind that the present invention also encompasses an article comprising a computer readable medium having stored thereon computer readable instructions for performing embodiments of the present technology. The computer readable medium can include, for example, a semiconductor, magnetic, photomagnetic, optical, or other form of computer readable medium for storing computer readable code. Furthermore, The invention also encompasses an apparatus for practicing embodiments of the invention. Such devices may include dedicated and/or programmable circuitry to perform the tasks associated with embodiments of the present invention. Examples of such devices include general purpose computers and/or special purpose computing devices (when properly programmed), and may include computer/computing devices and dedicated/programmable circuits for various tasks related to embodiments of the present invention. combination.

Embodiments of the present invention are directed to methods and apparatus for controlling plasma generation in a plasma processing chamber to reduce the effective residence time of by-product gases in a plasma processing chamber. The effective residence time can be defined as the average time that the gas/plasma composition is present on the substrate while the plasma is in an "etched" state (eg, according to a normal etch recipe). Embodiments of the present invention seek to reduce the effective dwell time by RF power modulation to reduce the plasma etch state duration to, for example, physically move from above the wafer to the wafer than the plasma/gas component The outer area takes less time. For example, if a given chamber has a normal (previous technical formulation) gas residence time of 20 milliseconds, and according to an embodiment of the invention, the radio frequency (RF) power supply time is only 5 milliseconds in 20 milliseconds, effectively staying The time can be roughly considered to be 5 milliseconds, which is about 25% of 20 milliseconds.

Regarding the problem of non-uniformity, the inventors conclude that the by-product gas concentration increases toward the edge of the substrate relative to the concentration of by-product gas present at the center of the substrate. This is because in most chambers, by-product gases move from the center of the substrate toward the edge of the substrate before being discharged through the side of the chamber or the lower portion of the chamber or both. The difference in by-product gas concentration across different regions of the substrate may be a contributing factor to process non-uniformity.

Reducing gas residence time (i.e., time to stay in the chamber before the gas is expelled) can improve process uniformity (which can involve etch uniformity, deposition uniformity, etch rate uniformity, deposition rate uniformity, etch depth) Uniformity and/or deposition thickness uniformity, depending on the type of treatment involved. As is generally known, the gas residence time is related to the volume of the plasma on the substrate, the pumping speed of the exhaust pump unit, and the process gas pressure. There is a lower limit to the amount by which the gas residence time can be reduced, because for example, for a certain pumping speed and pressure, the plasma volume cannot be reduced without limitation.

In accordance with one or more embodiments of the present invention, the gas residence time is "effectively" reduced by reducing plasma reactions to at least a portion of the processing time. As the term is used herein, processing time means the time required to process a substrate according to a given formulation. In accordance with one or more embodiments of the present invention, the plasma processing chamber operates in a normal processing mode for a portion of the processing time duration in accordance with the processing recipe provided. For another part of the processing time duration, electricity The slurry processing chamber operates in a "decrease" mode, thereby reducing the plasma generating energy (RF or microwave or other forms of energy generated by the plasma) to reduce or stop the reaction with the substrate exposed areas.

Alternatively, in accordance with one or more embodiments of the present invention, the gas residence time is "effectively" reduced by reducing plasma reactions to at least a portion of the "true" gas residence time. As used herein, the term "real" gas residence time means the time that the gas actually spends in the chamber and the volume of gas contained in the chamber (which is therefore related to gas pressure and volume) divided by the gas in the chamber. The rate of removal rate. In accordance with one or more embodiments of the present invention, the plasma processing chamber operates in a normal processing state for a portion of the true gas residence time duration in accordance with the provided processing recipe. For another portion of the true gas residence time duration, the plasma processing chamber operates in a "decrease" mode, thereby reducing the plasma generating energy (RF or microwave or other forms of energy generated by the plasma) to reduce or stop the substrate The reaction in the exposed area.

During the "decrease" mode time, the reaction by-product gas moves toward the edge of the substrate, and the secondary reaction with the exposed portion of the substrate is not significantly performed. Once the mode time is reduced, the plasma generating energy is again increased to process the substrate in a full level. In one or more embodiments, the reactive gas flowing into the chamber remains unchanged during the "reduce mode" time. In one or more embodiments, the length of the interval can range from 1 msec to the full length of the etching step.

In one or more embodiments, the plasma is actively monitored to control the start and end of the reduced mode. In one or more embodiments, the illuminating device is used to emit light into the plasma processing region and to monitor the changed light across the plasma processing region. For example, light can be changed by absorbing a certain portion of its wavelength. For example, light can be changed by emitting fluorescent light. Regardless, the system monitors the changed light and compares it to two threshold values as a function of wavelength.

If the parameter (for example, the intensity of the absorbed wavelength or the intensity of the emitted fluorescent wavelength) equals or exceeds the first critical value, the plasma is controlled to enter the reduced mode. Once in the reduction mode, the reaction is reduced or stopped and the by-product gas concentration is reduced over time. If the parameter is equal to or below the second threshold, the plasma is controlled to exit the reduced mode. After jumping out of the reduction mode, for example, the reaction will increase back to the full level. In the context of embodiments of the invention, the reduced mode refers to a lower RF power level compared to the normal etch mode and may include a plasma off state. In accordance with an embodiment of the present invention, for example, to avoid the complexity and delay associated with plasma reignition and stabilization, the plasma is greatly reduced during the mode reduction but is not completely extinguished. According to another embodiment of the invention, as another example, the plasma can be turned off during the mode reduction.

The features and advantages of the present invention will be more fully understood from the following description and description.

In accordance with an embodiment of the present invention, FIG. 2 shows a simplified diagram of a portion of an inventive chamber for reducing effective gas residence time to improve uniformity. Referring to FIG. 2, a plasma processing system having at least one plasma processing chamber 204 includes a lower electrode 206 for supporting a substrate 208 during processing. The chamber top plate 210, for example, the upper electrode in the case of a capacitively coupled plasma processing chamber, or the dielectric window in the case of an inductively coupled plasma processing chamber, forms the upper boundary of the plasma processing region 212. Light emitting device 214 (eg, in the form of a light source having a collimator) emits light through plasma processing region 212. The emitted light can be monochromatic (eg, laser) or can be broadband. As the light traverses the plasma processing zone 212, the light passes through the plasma and/or gas and/or materials present in the plasma processing zone 212 and is altered. The altered light is received by the light-receiving device 220. In the example of Figure 2, the light-receiving device 220 represents an optical emission spectrometer (OES). A lens 222 can be provided to focus the changed light onto the OES sensor.

Light-receiving device 220 can include an analysis sub-unit that compares parameters of the changed light (eg, the intensity of the absorbed wavelength or the intensity of the emitted fluorescent wavelength) and two thresholds and provides a signal responsive to the analysis. If the parameter (for example, the intensity of the absorbed wavelength or the intensity of the emitted fluorescent wavelength) is equal to or exceeds the first critical value, it is communicated by the controller 280 (which is in communication with the light-receiving device 220 and may be integrated with the light-receiving device 220 or It may be a separate component that transmits a signal to the RF power supply 240 (representing the plasma generating power in the example of Figure 2) to control the plasma (e.g., reduce RF power) to enter the reduced mode. Once in the reduction mode, the reaction is reduced or stopped and the by-product gas concentration is reduced over time. If the parameter is equal to or below the second threshold, another signal is sent to the RF power supply 240 by the controller 280 to control the plasma (e.g., increase RF power) to jump out of the reduced mode. After jumping out of the reduction mode, for example, the reaction will increase back to the full level.

In accordance with an embodiment of the present invention, FIG. 3 shows a simplified diagram of a portion of an inventive chamber to reduce effective gas residence time to improve uniformity. Referring to FIG. 3, a plasma processing system having at least one plasma processing chamber 304 includes a lower electrode 306 for supporting a substrate 308 during processing. The chamber top plate 310, for example, the upper electrode in the case of a capacitively coupled plasma processing chamber, or the dielectric window in the case of an inductively coupled plasma processing chamber, forms the upper boundary of the plasma processing region 312. Light emitting devices (eg, in the form of light sources having parallel light pipes) emit light through the plasma processing region 312. The emitted light can be monochromatic (eg, laser) or can be broadband.

When light traverses the plasma processing zone 312, the light passes through the plasma and/or gas and/or The material present in the plasma processing zone 312 is altered. The change light is received by the light-receiving device. In the example of FIG. 3, the light-receiving device represents a photodiode 328 and an interference filter 330.

The light-receiving device can include an analysis sub-unit that compares parameters of the changed light (eg, the intensity of the absorbed wavelength or the intensity of the emitted fluorescent wavelength) and the two thresholds and provides a signal responsive to the analysis. If the parameter (for example, the intensity of the absorbed wavelength or the intensity of the emitted fluorescent wavelength) is equal to or exceeds the first critical value, then transmitting (using a controller such as that described in FIG. 2) to the RF power supply 340 (in the figure) The example of 3 represents plasma generation of power) to control the plasma (eg, reduce RF power) to enter a reduced mode. Once in the reduction mode, the reaction is reduced or stopped and the by-product gas concentration is reduced over time. If the parameter is equal to or below the second threshold, another signal is sent to the RF power supply 340 to control the plasma (e.g., increase RF power) to jump out of the reduced mode. After jumping out of the reduction mode, for example, the reaction will increase back to the full level.

In accordance with an embodiment of the invention, Figure 4 shows a graph of fluorescence intensity or absorption as a function of time. During time T1, the plasma processing chamber operates in normal mode and is processed at the full level. The signal strength 402 is monitored and if the signal strength 402 equals or exceeds the threshold 420, the plasma is controlled to change into the reduced mode by varying the RF power. The reduction mode duration is displayed as time T2. Continuing to monitor the signal strength 402 and if the signal strength 402 is equal to or falls below the threshold 430, the plasma is controlled to change the RF power to jump out of the reduced mode. In the example of Figure 4, after the bounce reduction mode, the plasma processing returns to the full level. In one or more embodiments, the flow rate of reactant gases entering the chamber remains constant during times T1 and T2.

In accordance with an embodiment of the present invention, FIG. 5 shows a graph of the wavelength of the signal intensity versus fluorescence (which is emitted after the laser beam is emitted from the illumination device and received by the light-receiving device). As seen in Figure 5, a laser with a wavelength WL emits some of the gas of the by-product gas in the plasma processing zone with a fluorescent light of wavelength W1. By monitoring the intensity of the fluorescence, the concentration of by-product gas can be approximated or calculated and compared to the two thresholds in the manner discussed earlier.

In accordance with an embodiment of the present invention, FIG. 6 shows a plot of signal intensity versus wavelength of absorbed light (after the wide (white) spectral beam is emitted from the illumination device and absorbed by the light-receiving device). As seen in Figure 6, the by-product gas absorbs some portions of the wavelength WS of the white spectrum. By monitoring how much light is absorbed at the wavelength WS, the byproduct gas concentration can be approximated or calculated and compared to the two thresholds in the manner discussed earlier.

Figure 7 shows an example of reducing the effective residence time of a gas according to an embodiment of the invention. To improve the uniformity. The method is practiced in a plasma system having at least one plasma processing chamber. The chamber includes at least one lower electrode for supporting the substrate and a chamber top plate disposed above the lower electrode such that the plasma processing region is present between the upper surface of the substrate and the chamber top plate during processing.

The plasma processing chamber also includes a plasma generating power source for providing energy to generate plasma from the supplied reactive gas in the plasma processing zone. In step 702, a light emitting device for emitting first light into the plasma processing region is provided. In step 704, a light harvesting device is provided for receiving the second light, the second light representing a changed form of the first light (after the first light passes through the plasma processing region). In step 706, a logic is provided for analyzing the second light to determine if the parameter of the second light exceeds a first threshold or falls below a second threshold. If the parameter of the second light is equal to or exceeds the first threshold (712), step 708 includes reducing the amount of energy produced by the plasma provided by the plasma. If not (step 712), the program returns to step 702 to continue monitoring the emitted light.

If the parameter of the second light is equal to or falls below the second critical value (714). Step 710 includes increasing the amount of energy produced by the plasma provided by the plasma generating power source. If not (step 714), the program returns to step 702 to continue monitoring the emitted light. The steps of Figure 7 can be performed repeatedly (arrow 720) until the substrate processing is completed.

As can be appreciated from the foregoing description, embodiments of the present invention improve uniformity by effectively reducing gas residence time. If the RF power supply is modulated to enter or exit the reduced mode, the modulation between the reduced mode and the full processing mode may be in the range of milliseconds, which tends to be too long without significantly affecting the electronic temperature. However, the effective gas residence time can be reduced to the extent that has not previously been achieved (by reducing chamber pressure, chamber volume limitations, or increasing the rate of pumping rate). By reducing the effective gas residence time, the uniformity is advantageously improved.

Although the examples herein have been discussed in the context of reducing non-uniformities in the difference in by-product concentration between the edge regions of the substrate and the central region of the substrate, embodiments of the present invention are applicable to monitoring reaction by-product concentrations or precursors. Body concentration and modulation of RF power between normal and reduced modes to reduce their effective residence time.

For example, to affect the amount of polymer deposition, the polymer precursor concentration can be monitored to control parameters of normal and reduced modes (eg, duration or RF power level). As is known, certain etching processes may involve balancing the deposition and etching mechanisms/substeps to achieve the desired Etching results. In these etching applications, it is desirable to control polymer deposition because, for example, too much or too little polymer deposition can result in, for example, reduced etch rates, non-uniformities, defective etch profiles, and other undesirable results. Alternatively or additionally, embodiments of the invention discussed above may be adapted to monitor the concentration of precursors and to modulate normal operating time and to reduce the duration of mode time and/or RF power levels to provide for controlled etching. Additional control means.

Furthermore, the ability to control the concentration of polymer precursors or by-products while etching the substrate to quickly respond to sensor measurements can also address the previously described aspect ratio related etch (ARDE) issues. For example, the concentration of etching by-products in these high aspect ratio holes and grooves can be better controlled by giving etch byproducts more time to diffuse higher aspect ratio characteristics during reduced mode operation periods or pulse waves. , thereby mitigating ARDE.

While the invention has been described in terms of several preferred embodiments, the modifications and The various examples are provided herein, but are intended to be illustrative and not restrictive. Also, the names of the invention and the summary of the invention are provided herein for convenience and should not be construed as a limitation of the scope of the claims. In addition, the abstract is written in a highly abbreviated form and is provided here for convenience, and therefore should not be used to interpret or limit the entire invention indicated in the scope of the patent application. If the term "group" is used herein, the term is intended to encompass a mathematical meaning that is generally understood to encompass zero, one, or greater than one. It should also be noted that there are many alternative ways of implementing the methods and apparatus of the present invention. It is therefore intended that the appended claims be construed as being

204‧‧‧The plasma processing chamber

206‧‧‧ lower electrode

208‧‧‧Substrate

210‧‧‧Cable ceiling

212‧‧‧The plasma processing area

214‧‧‧Lighting equipment

220‧‧‧Lighting equipment

222‧‧‧ lens

240‧‧‧RF power supply

280‧‧‧ Controller

Claims (19)

A plasma processing system having at least one plasma processing chamber for processing a substrate, the plasma processing system comprising: a lower electrode for supporting the substrate; a chamber top plate disposed above the lower electrode, Having a plasma processing zone between the upper surface of the substrate and the top plate of the chamber during the processing; a plasma generating a power source for providing energy to be generated from the supplied reactive gas in the plasma processing zone a illuminating device for emitting a first light into the plasma processing region; a light collecting device for receiving the second light, the second light representing the first light passing through the plasma processing region a modified form of the first light; and a controller for analyzing the second light to determine that a parameter of the second light is equal to or exceeds a first threshold, or equal to or falls within a second threshold Wherein the first threshold value represents a first concentration of by-product gas generated from a reaction of the plasma with an exposed surface of the substrate, and the second threshold value represents a second concentration of the by-product gas, wherein Second light When the parameter is equal to or exceeds the first threshold, the controller transmits a first signal to reduce the amount of energy generated by the plasma generated by the plasma generating power to the plasma generated in relation to the reduced mode generated by the plasma. An energy level that adjusts a plasma generation energy level between a complete mode of plasma generation and a reduction mode generated by the plasma, and controls an effective gas residence time of the by-product gas on the upper surface of the substrate, if the second light The parameter is equal to or falls below the second threshold, and the controller transmits a second signal to increase the amount of plasma generated energy generated by the plasma generating power source to a complete mode generated by the plasma. The associated plasma produces an energy level wherein the plasma generation energy level associated with the reduced mode produced by the plasma is sufficiently low to minimize or stop the reaction of the plasma with the exposed surface of the substrate such that the concentration of the byproduct gas In the reduction mode produced by the plasma, it decreases over time, and wherein the plasma generation energy level associated with the complete mode produced by the plasma is sufficient To increase the exposed surfaces of the plasma reaction with the substrate to a full level, wherein the concentration of the product gases in the full mode of the generated plasma increases with time. The plasma processing system of claim 1, wherein the plasma processing chamber is a narrow gap chamber, wherein a gap between the upper surface of the lower electrode and the top plate of the chamber is less than the base 10% of the plate diameter, and the by-product is reduced by selecting the first threshold and the second threshold for reducing the effective residence time of the by-product gas in comparison to continuous operation of the complete mode of the plasma generation The effective residence time of the gas is reduced. A plasma processing system according to claim 1, wherein the illuminating device is configured to emit a broad spectrum of light. A plasma processing system according to claim 1, wherein the illuminating device is configured to emit a laser beam. A plasma processing system according to claim 1, wherein the chamber top plate represents a dielectric window. A plasma processing system according to claim 1, wherein the illuminating device is a light source having a collimator. The plasma processing system of claim 1, wherein the light-receiving device is an optical emission spectrometer. The plasma processing system of claim 1, wherein the controller further limits the total time that the plasma generates power in the complete mode to reduce the effective residence time of the plasma by-product component to a steady state stay. The time is shorter, wherein the steady state residence time is the amount of time (normal gas residence time) required for the plasma component to physically move from above the substrate to the region outside the substrate, wherein the effective residence time is to The normal gas residence time is calculated by multiplying the ratio of the time that the plasma produces the power source in the full mode. A plasma processing system according to claim 8 wherein the effective residence time is no more than about 25% of the normal gas residence time. A plasma processing system according to claim 1, wherein the plasma generation energy level associated with the reduced mode produced by the plasma is sufficiently low to minimize the reaction of the plasma with the exposed surface of the substrate while ensuring The plasma is not completely extinguished. A plasma processing system according to claim 1, wherein the plasma processing chamber is configured to maintain a fixed flow rate of the supplied reaction gas between the reduced mode and the full mode. A plasma processing system having at least one plasma processing chamber for processing a substrate, the plasma processing system comprising: a lower electrode for supporting the substrate; and a plasma generating a power source for supplying energy The supplied reaction gas produces a plasma which is produced in a plasma processing zone above the substrate; a light emitting device for emitting first light into the plasma processing region; a light collecting device for receiving second light, the second light representing the first light after the first light passes through the plasma processing region An altered form, wherein the second light is generated after a byproduct gas absorbs portions of the wavelength of the first light; and a controller for analyzing the second light and responding to adjust the plasma generation An energy level, the controller determines whether a parameter of the second light is equal to or exceeds a first threshold, or equals or falls below a second threshold, wherein the first threshold represents from the plasma and the a first concentration of by-product gas generated in the reaction of the exposed surface of the substrate, and the second threshold represents a second concentration of the by-product gas, wherein if the parameter is equal to or exceeds the first threshold, the controller transmits a first a signal for reducing the amount of energy generated by the plasma provided by the plasma generating power source to a plasma generating energy level associated with the reduced mode produced by the plasma, and wherein the parameter equals or falls within the second threshold The controller transmits a second signal to increase the amount of energy generated by the plasma generated by the plasma generating power to a plasma generating energy level associated with the complete mode of plasma generation, wherein the plasma is generated The reduction mode associated plasma generation energy level is sufficiently low to minimize or stop the reaction of the plasma with the exposed surface of the substrate, and wherein the plasma generation energy level system associated with the complete mode produced by the plasma is sufficiently high To increase the reaction of the plasma with the exposed surface of the substrate to a complete level, and wherein the plasma generation energy levels associated with the reduced mode and the complete mode are respectively sufficiently low and high enough to ensure that in the full mode The concentration of the by-product gas increases over time, and in the reduced mode, the concentration of the by-product gas decreases over time relative to the concentration of one of the by-product gases provided by the complete mode. A plasma processing system according to claim 12, wherein the plasma generation energy level associated with the reduced mode produced by the plasma is sufficiently low to minimize the reaction of the plasma with the exposed surface of the substrate while ensuring The plasma is not completely extinguished. A plasma processing system according to claim 12, wherein the plasma processing chamber is configured to maintain a fixed flow rate of the supplied reaction gas between the reduced mode and the full mode. A plasma processing system having at least one plasma processing chamber for etching a substrate, the plasma processing system comprising: a lower electrode for supporting the substrate; a chamber top plate disposed above the lower electrode, To make a plasma processing area in a treatment period Between the upper surface of the substrate and the top plate of the chamber; a plasma generates a power source for supplying energy to generate plasma from the supplied reaction gas in the plasma processing region; Transmitting a first light into the plasma processing region; a light collecting device for receiving a second light, the second light representing a changed form of the first light after the first light passes through the plasma processing region And a controller for determining a plasma generation level during etching of the substrate, the controller controlling an effective residence time of the by-product gas on the upper surface of the substrate by: performing the second light A parameter (representing a concentration of the byproduct gas generated from the reaction of the plasma with the exposed upper surface of the substrate) is compared to a higher threshold and a lower threshold (representing a concentration of the byproduct gas) And based on the comparison, a decision is made between increasing the plasma generation power to a complete mode of plasma generation based on the lower threshold (where the concentration of the byproduct gas is pushed with time) Increases), and based on the higher threshold will reduce the power to reduce the plasma generator generated plasma mode (wherein the concentration of the by-product gas decreases with time). The plasma processing system of claim 15, wherein the plasma generation level is selected based on comparing at least one of the associated higher and lower thresholds with a parameter of the second light, and responding The plasma generation level is adjusted to control the effective residence time of the by-product gas. The plasma processing system of claim 16, wherein: 1) if the parameter of the second light is equal to or exceeds the higher threshold, selecting a reduction mode generated by the plasma, wherein the higher threshold is represented by Selecting the first concentration of the byproduct gas generated from the reaction of the plasma with the exposed upper surface of the substrate; and 2) selecting the electrical energy if the parameter of the second light is equal to or falls below the lower threshold The complete pattern of pulp production. A plasma processing system according to claim 17 wherein the effective residence time is no more than about 25% of a normal gas residence time when only the full mode is used. The plasma processing system of claim 15, wherein the plasma processing chamber is a narrow gap chamber, wherein a gap between the upper surface of the lower electrode and the top plate of the chamber is less than the diameter of the substrate 10%.